I made these homemade sound cylinders using lotion containers that my mom, sister, and I have been saving for about a year (specifically for this purpose). Each container has a match, and I put lentils in 2, marbles in 2, and bells in 2. There are stickers on the bottoms of the containers, so that O can self check to see if she is correct. Here are directions for this work. We've done this work once, and it didn't go well. O was not at all interested in listening to the sound cylinders, and she only wanted to open the containers. We'll try it again once we start back with our Montessori school in a few weeks (or whenever the new shelf is built!).